drm/msm/dsi: remove the drm_bridge_attach fallback

All the bridges that are being used with the MSM DSI hosts have been
converted to support DRM_BRIDGE_ATTACH_NO_CONNECTOR. Drop the fallback
code and require DRM_BRIDGE_ATTACH_NO_CONNECTOR to be supported by the
downstream bridges.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/582209/
Link: https://lore.kernel.org/r/20240309-fd-dsi-cleanup-bridges-v1-1-962ebdba82ed@linaro.org

drivers/gpu/drm/msm/dsi/dsi_manager.c

@@ -465,6 +465,7 @@ int msm_dsi_manager_ext_bridge_init(u8 id, struct drm_bridge *int_bridge)
 	struct drm_device *dev = msm_dsi->dev;
 	struct drm_encoder *encoder;
 	struct drm_bridge *ext_bridge;
+	struct drm_connector *connector;
 	int ret;
 
 	ext_bridge = devm_drm_of_get_bridge(&msm_dsi->pdev->dev,
@@ -474,36 +475,21 @@ int msm_dsi_manager_ext_bridge_init(u8 id, struct drm_bridge *int_bridge)
 
 	encoder = int_bridge->encoder;
 
-	/*
-	 * Try first to create the bridge without it creating its own
-	 * connector.. currently some bridges support this, and others
-	 * do not (and some support both modes)
-	 */
 	ret = drm_bridge_attach(encoder, ext_bridge, int_bridge,
 			DRM_BRIDGE_ATTACH_NO_CONNECTOR);
-	if (ret == -EINVAL) {
-		/*
-		 * link the internal dsi bridge to the external bridge,
-		 * connector is created by the next bridge.
-		 */
-		ret = drm_bridge_attach(encoder, ext_bridge, int_bridge, 0);
-		if (ret < 0)
-			return ret;
-	} else {
-		struct drm_connector *connector;
-
-		/* We are in charge of the connector, create one now. */
-		connector = drm_bridge_connector_init(dev, encoder);
-		if (IS_ERR(connector)) {
-			DRM_ERROR("Unable to create bridge connector\n");
-			return PTR_ERR(connector);
-		}
+	if (ret)
+		return ret;
 
-		ret = drm_connector_attach_encoder(connector, encoder);
-		if (ret < 0)
-			return ret;
+	connector = drm_bridge_connector_init(dev, encoder);
+	if (IS_ERR(connector)) {
+		DRM_ERROR("Unable to create bridge connector\n");
+		return PTR_ERR(connector);
 	}
 
+	ret = drm_connector_attach_encoder(connector, encoder);
+	if (ret < 0)
+		return ret;
+
 	return 0;
 }